Embodiments relate generally to signal processing and, more particularly, to analog to digital conversion.
In some moderate bandwidth sigma-delta analog-to-digital converter (ADC) applications, flicker noise may be a significant problem. Examples of such applications may include audio and GSM, which may be economically significant markets. Flicker noise may be noise that is characterized by a 1/f relationship such that lower frequencies tend to contribute more to the noise. This flicker noise problem may be a significant issue with circuits fabricated with CMOS devices having a size of 45 nm and 65 nm.
Attempts have been made to reduce flicker noise and its effects. One approach to reduce flicker noise may be to increase the devices sizes away from 45 nm. The result, however, may be an ADC that may be 2 to 4 times the size if flicker noise were not a problem. In addition to the unwanted size increase, parasitic capacitances may also increase. To combat this, current consumption may be increased to keep the parasitic poles from decreasing. It is known that low frequency parasitic poles may cause instability within ADCs.
Therefore, there remains, as yet an unfulfilled need for an ADC that reduces the impact of flicker noise but also provide a small device/circuit size and avoids impacting current and power consumption.